import numpy as np

import pytest

import matplotlib as mpl

from matplotlib.testing import _has_tex_package

from matplotlib.testing.decorators import check_figures_equal, image_comparison

import matplotlib.pyplot as plt

if not mpl.checkdep_usetex(True):

pytestmark = pytest.mark.skip('Missing TeX of Ghostscript or dvipng')

@image_comparison(

baseline_images=['test_usetex'],

extensions=['pdf', 'png'],

style="mpl20")

def test_usetex():

mpl.rcParams['text.usetex'] = True

fig, ax = plt.subplots()

kwargs = {"verticalalignment": "baseline", "size": 24,

"bbox": dict(pad=0, edgecolor="k", facecolor="none")}

ax.text(0.2, 0.7,

# the \LaTeX macro exercises character sizing and placement,

# \left[ ... \right\} draw some variable-height characters,

# \sqrt and \frac draw horizontal rules, \mathrm changes the font

r'\LaTeX\ $\left[\int\limits_e^{2e}'

r'\sqrt\frac{\log^3 x}{x}\,\mathrm{d}x \right\}$',

**kwargs)

ax.text(0.2, 0.3, "lg", **kwargs)

ax.text(0.4, 0.3, r"$\frac{1}{2}\pi$", **kwargs)

ax.text(0.6, 0.3, "$p^{3^A}$", **kwargs)

ax.text(0.8, 0.3, "$p_{3_2}$", **kwargs)

for x in {t.get_position()[0] for t in ax.texts}:

ax.axvline(x)

for y in {t.get_position()[1] for t in ax.texts}:

ax.axhline(y)

ax.set_axis_off()

@check_figures_equal()

def test_empty(fig_test, fig_ref):

mpl.rcParams['text.usetex'] = True

fig_test.text(.5, .5, "% a comment")

@check_figures_equal()

def test_unicode_minus(fig_test, fig_ref):

mpl.rcParams['text.usetex'] = True

fig_test.text(.5, .5, "$-$")

fig_ref.text(.5, .5, "\N{MINUS SIGN}")

def test_mathdefault():

plt.rcParams["axes.formatter.use_mathtext"] = True

fig = plt.figure()

fig.add_subplot().set_xlim(-1, 1)

# Check that \mathdefault commands generated by tickers don't cause

# problems when later switching usetex on.

mpl.rcParams['text.usetex'] = True

fig.canvas.draw()

@pytest.mark.parametrize("fontsize", [8, 10, 12])

def test_minus_no_descent(fontsize):

# Test special-casing of minus descent in DviFont._height_depth_of, by

# checking that overdrawing a 1 and a -1 results in an overall height

# equivalent to drawing either of them separately.

mpl.style.use("mpl20")

mpl.rcParams['font.size'] = fontsize

heights = {}

fig = plt.figure()

for vals in [(1,), (-1,), (-1, 1)]:

fig.clear()

for x in vals:

fig.text(.5, .5, f"${x}$", usetex=True)

fig.canvas.draw()

# The following counts the number of non-fully-blank pixel rows.

heights[vals] = ((np.array(fig.canvas.buffer_rgba())[..., 0] != 255)

.any(axis=1).sum())

assert len({*heights.values()}) == 1

@pytest.mark.parametrize('pkg', ['xcolor', 'chemformula'])

def test_usetex_packages(pkg):

if not _has_tex_package(pkg):

pytest.skip(f'{pkg} is not available')

mpl.rcParams['text.usetex'] = True

fig = plt.figure()

text = fig.text(0.5, 0.5, "Some text 0123456789")

fig.canvas.draw()

mpl.rcParams['text.latex.preamble'] = (

r'\PassOptionsToPackage{dvipsnames}{xcolor}\usepackage{%s}' % pkg)

fig = plt.figure()

text2 = fig.text(0.5, 0.5, "Some text 0123456789")

fig.canvas.draw()

np.testing.assert_array_equal(text2.get_window_extent(),

text.get_window_extent())

@pytest.mark.parametrize(

"preamble",

[r"\usepackage[full]{textcomp}", r"\usepackage{underscore}"],

)

def test_latex_pkg_already_loaded(preamble):

plt.rcParams["text.latex.preamble"] = preamble

fig = plt.figure()

fig.text(.5, .5, "hello, world", usetex=True)

fig.canvas.draw()

def test_usetex_with_underscore():

plt.rcParams["text.usetex"] = True

df = {"a_b": range(5)[::-1], "c": range(5)}

fig, ax = plt.subplots()

ax.plot("c", "a_b", data=df)

ax.legend()

ax.text(0, 0, "foo_bar", usetex=True)

plt.draw()